1 /* $OpenBSD: exec.c,v 1.18 2005/08/08 08:05:34 espie Exp $ */ 2 /*- 3 * Copyright (c) 1991, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <sys/param.h> 32 #include <sys/types.h> 33 #include <sys/uio.h> 34 #include <errno.h> 35 #include <unistd.h> 36 #include <limits.h> 37 #include <stdlib.h> 38 #include <string.h> 39 #include <strings.h> 40 #include <stdio.h> 41 #include <paths.h> 42 #include <stdarg.h> 43 #include <alloca.h> 44 45 extern char **environ; 46 47 int 48 execl(const char *name, const char *arg, ...) 49 { 50 va_list ap; 51 char **argv; 52 int n; 53 54 va_start(ap, arg); 55 n = 1; 56 while (va_arg(ap, char *) != NULL) 57 n++; 58 va_end(ap); 59 argv = alloca((n + 1) * sizeof(*argv)); 60 if (argv == NULL) { 61 errno = ENOMEM; 62 return (-1); 63 } 64 va_start(ap, arg); 65 n = 1; 66 argv[0] = (char *)arg; 67 while ((argv[n] = va_arg(ap, char *)) != NULL) 68 n++; 69 va_end(ap); 70 return (execve(name, argv, environ)); 71 } 72 73 int 74 execle(const char *name, const char *arg, ...) 75 { 76 va_list ap; 77 char **argv, **envp; 78 int n; 79 80 va_start(ap, arg); 81 n = 1; 82 while (va_arg(ap, char *) != NULL) 83 n++; 84 va_end(ap); 85 argv = alloca((n + 1) * sizeof(*argv)); 86 if (argv == NULL) { 87 errno = ENOMEM; 88 return (-1); 89 } 90 va_start(ap, arg); 91 n = 1; 92 argv[0] = (char *)arg; 93 while ((argv[n] = va_arg(ap, char *)) != NULL) 94 n++; 95 envp = va_arg(ap, char **); 96 va_end(ap); 97 return (execve(name, argv, envp)); 98 } 99 100 int 101 execlp(const char *name, const char *arg, ...) 102 { 103 va_list ap; 104 char **argv; 105 int n; 106 107 va_start(ap, arg); 108 n = 1; 109 while (va_arg(ap, char *) != NULL) 110 n++; 111 va_end(ap); 112 argv = alloca((n + 1) * sizeof(*argv)); 113 if (argv == NULL) { 114 errno = ENOMEM; 115 return (-1); 116 } 117 va_start(ap, arg); 118 n = 1; 119 argv[0] = (char *)arg; 120 while ((argv[n] = va_arg(ap, char *)) != NULL) 121 n++; 122 va_end(ap); 123 return (execvp(name, argv)); 124 } 125 126 int 127 execv(const char *name, char * const *argv) 128 { 129 (void)execve(name, argv, environ); 130 return (-1); 131 } 132 133 int 134 execvp(const char *name, char * const *argv) 135 { 136 char **memp; 137 int cnt, lp, ln, len; 138 char *p; 139 int eacces = 0; 140 char *bp, *cur, *path, buf[MAXPATHLEN]; 141 142 /* 143 * Do not allow null name 144 */ 145 if (name == NULL || *name == '\0') { 146 errno = ENOENT; 147 return (-1); 148 } 149 150 /* If it's an absolute or relative path name, it's easy. */ 151 if (strchr(name, '/')) { 152 bp = (char *)name; 153 cur = path = NULL; 154 goto retry; 155 } 156 bp = buf; 157 158 /* Get the path we're searching. */ 159 if (!(path = getenv("PATH"))) 160 path = _PATH_DEFPATH; 161 len = strlen(path) + 1; 162 cur = alloca(len); 163 if (cur == NULL) { 164 errno = ENOMEM; 165 return (-1); 166 } 167 strlcpy(cur, path, len); 168 path = cur; 169 while ((p = strsep(&cur, ":"))) { 170 /* 171 * It's a SHELL path -- double, leading and trailing colons 172 * mean the current directory. 173 */ 174 if (!*p) { 175 p = "."; 176 lp = 1; 177 } else 178 lp = strlen(p); 179 ln = strlen(name); 180 181 /* 182 * If the path is too long complain. This is a possible 183 * security issue; given a way to make the path too long 184 * the user may execute the wrong program. 185 */ 186 if (lp + ln + 2 > (int)sizeof(buf)) { 187 struct iovec iov[3]; 188 189 iov[0].iov_base = "execvp: "; 190 iov[0].iov_len = 8; 191 iov[1].iov_base = p; 192 iov[1].iov_len = lp; 193 iov[2].iov_base = ": path too long\n"; 194 iov[2].iov_len = 16; 195 (void)writev(STDERR_FILENO, iov, 3); 196 continue; 197 } 198 memcpy(buf, p, lp); 199 buf[lp] = '/'; 200 memcpy(buf + lp + 1, name, ln); 201 buf[lp + ln + 1] = '\0'; 202 203 retry: (void)execve(bp, argv, environ); 204 switch(errno) { 205 case E2BIG: 206 goto done; 207 case EISDIR: 208 case ELOOP: 209 case ENAMETOOLONG: 210 case ENOENT: 211 break; 212 case ENOEXEC: 213 for (cnt = 0; argv[cnt]; ++cnt) 214 ; 215 memp = alloca((cnt + 2) * sizeof(char *)); 216 if (memp == NULL) 217 goto done; 218 memp[0] = "sh"; 219 memp[1] = bp; 220 memcpy(memp + 2, argv + 1, cnt * sizeof(char *)); 221 (void)execve(_PATH_BSHELL, memp, environ); 222 goto done; 223 case ENOMEM: 224 goto done; 225 case ENOTDIR: 226 break; 227 case ETXTBSY: 228 /* 229 * We used to retry here, but sh(1) doesn't. 230 */ 231 goto done; 232 case EACCES: 233 eacces = 1; 234 break; 235 default: 236 goto done; 237 } 238 } 239 if (eacces) 240 errno = EACCES; 241 else if (!errno) 242 errno = ENOENT; 243 done: 244 return (-1); 245 } 246
